Forest Development in the Adirondacks 43 
at Plattsburg and these species (excepting bear berry) with two 
shrub oaks, Quercus ilicifolia and (. prinoides, in the Albany 
pine Peaths: The sand plain of the Oswegatchie is rather unique 
in this that while it presents certain species characteristic of 
bogs or swamps (Oryzopsis aspertfolia, Solidago wliginosa) it 
supports in reality a dry-heath like vegetation of more pro- 
nounced character than any of the others. This is shown 
notably by the extent of the ground cover of lichens (Cladonia 
rangiferina, alpestris and pyxidata), Polytrichum and by Vac- 
cimum augustifolium, canadense and vacillans (though the first 
two of these occur in sphagnum bogs). The fact was pointed 
out in bulletin 3 (2 page —) that tamarack is the dominant 
invading forest species. All this points to the interesting fact 
that while this sand plain lies high enough above the water 
table to become very dry at the surface, it is in fact so low 
and flat as to shelter wet lands species, and while sphagnum 
does not occur and there is no peat formation, a very slight 
rise of the permanent water table would result in bog forma- 
tion quite as marked as in the Grasse River area. It should 
be mentioned here that in the Grasse River bog, Polytrichum 
(apparently the same species as in the Oswegatchie sand 
plain) is prominent in the drier mounds of sphagnum sedge 
meadow and that this moss and the lichens Cladonia rangi- 
ferina and pyxidata appear on the very slight elevations of the 
bog where sphagnums are excluded. While Cassandra does 
not occur on the Oswegatchie sand plain it often occurs in 
ereat abundance on non-peat and sphagnum covered sands 
(e. g., east end of Oneida Lake), so that really the difference 
between the dry heath and the wet heath is reduced merely to 
the occurrence of sphagnums in the latter case and its absence 
in the former. Floristically the two groups of associations 
are very similar. The suggestion arises that the edaphic con- 
ditions in the low sand ee despite the periodic surface drying 
are similar to those of sphagnum bogs. This suggestion is 
strengthened by the frequent occurrence of black spruce on the 
dry heath and by the aggressive invasion of it by tamarack, 
which as shown in bulletin 3 (2 fig. 30) is one of the note- 
